Now, I am kinda lost---do I just need to add a good PVR card (I was eyeing the Hauppauge 150), or do i need that plus a good video card, in addition to the software?
You'll at least need a video card with TV-out, (unless you plan on watching TV on your computer monitor). Other than that, any recent video card will do. An expensive video card does give you some bangs and whistles, but all that is necessary is good TV-out quality.
And, will the 150 let me connect to my VCR? Part of the drive for this is a desire to take all my old VHS and transfer to HD or DVDs and save space, as well as being able to record a few regular TV shows without killing myself to find a spot on a blank tape
Although I haven't tried it, I don't see why not. The 150 has the required composite inputs. One issue you may run into with commerical videos is Macrovision. I think this product
http://www.bestbuy.com/site/olspage.jsp?id=1074788291354&skuId=6296563&productCategoryId=cat08062&type=product is designed to get around Macrovision, but don't quote me on it.
The 150 (not MCE version) comes with a remote. I suppose you could use a mouse and keyboard just fine, if you wanted to.